The present invention relates to accessories for heavy-duty vacuum-type cleaning units such as those found in industrial applications, as well as in professional equipment kits and home workshop environments. Such equipment is referred to hereinafter as “cleaning units”, “vacuums”, or “cleaning equipment.” More particularly, the invention disclosed herein is an appliance which, when attached as an accessory to a heavy-duty vacuum cleaning unit attenuates exhaust port turbulence on such machines, providing an overall cleaner and safer work environment.
A vast range of accessories for heavy-duty and shop-type vacuum cleaners exists. For example, there exist carbon filter systems intended to be used as an add-on to such vacuum cleaners to capture volatile organic compounds emitted in waste or exhaust streams, which for purposes of this disclosure may be referred to as “post cycle supplemental filtration” given that the primary waste air flow results from intake air being drawn into one or more internal filters inherent to a vacuum cleaning unit. A prime example of such a post-cycle supplemental filtration unit is found at http://www.apsimplepsaltery.com/shopvac.htm. Another related concept is presented at http://www.instructables.com/id/Making-a-sound-baffle-for-loud-shop-vacuums/, where the do-it-yourself instructions provided are intended to result in a shop vacuum cleaner exhaust noise reduction baffle.
Numerous other examples of accessories for industrial and shop-type vacuums are to be found. The majority of these items, such as high efficiency particulate air (HEPA) filters, are directed largely to components and systems designed to inhibit the discharge of noxious substances or irritants and allergens into the waste air flow of a vacuum cleaner or cleaning system. Similarly, a smaller group of accessories attempt, as indicated by the latter example in the preceding paragraph, to minimize the noise level attendant with the operation of a powerful vacuum cleaner motor. For example, patent application U.S. Serial Number 20060179601, submitted by Crevling et al., discloses a removable internal air diffuser intended to reduce noise associated with the generation and discharge of high-speed airflows.
While it is known in the art that various aspects of the exhaust flow streams emanating from a variety of types of equipment may be effectively managed to bring about a reduction in the decibel level produced by many types of machines, there appears to be only an extremely limited body of physical solutions directed towards reducing the turbulence of vacuum cleaner exhaust flows, and this outcome appears to be an unintentional byproduct of other desired aspects of the few attachments and accessories that provide post-cycle supplemental filtration.
More particularly, a wide variety of exhaust airflow filters for various exhaust-generating units and systems are known in the art. In the case of vacuum cleaners and related systems, common—and rather similar—solutions are directed primarily at noise attenuation. The inventive concepts claiming to resolve the issue of high output-air-related noise levels involve a range of internal and external baffles, mufflers, and the like. For example, U.S. Pat. No. 8,261,406 granted to Kunz et al., covers a vacuum with multiple exhaust points, and claims the construction provides for quieter, lower velocity discharge of the air from the vacuum source. The operating principle is that the multiple exhaust points are supplied from a radially extending chamber that is defined between upper and lower panels. The radially extending chamber has both vertical and radial sections that operate to slow the velocity of the exhaust air to reduce the noise generated by the vacuum. Like Kunz, most of these concepts, when reduced to practice, are relatively simplistic in principle while complex in terms of their construction and number of parts. Moreover, apart from expensive and sensitive high-efficiency particulate filters geared towards allergen capture, and related components such as cartridges, frames, etc., few, if any of these filters, mufflers, or baffles are directed to limiting the discharge of fine particulates from the waste air stream, presumably on the assumption that filtration prior to the airflow reaching the motor is adequate.
More importantly, none of these accessories appears to be directed at effectively managing turbulent exhaust discharge flow, which can be highly problematic, for example by forcefully and powerfully disturbing particulates that have previously settled out of ambient air, or by unsettling fragile objects, for example precision tools or parts on a laboratory or workshop bench. A prime illustration of the problem raised is found in the example of a turbulent and powerful exhaust flow stirring up fine drywall dust that may have settled upon surfaces following the sanding of joint compound applied to seal the interstices of installed drywall panels. The scattering and random redistribution of fine particulate matter into the atmosphere of the immediate work area in large part defeats the attempts to clean with a shop-type vacuum cleaner, requiring laborious sweeping and wet mopping.
Therefore, given the heretofore unmet need of a device capable of reducing exhaust flow turbulence from a vacuum cleaning unit, while not diminishing the efficacy of the unit by reducing suction capacity or placing additional strain on the unit's motor, there is a clear need for an exhaust stream turbulence attenuating unit which is easily adapted and fitted to a broad range of vacuum cleaning units, which is low in cost, and which functions without diminishing the performance of the device to which it is attached.